I recently got what most people would consider a cheap and toy road bike as a gift. It came with very primitive RD and cassette (shimano SIS? I think). I enjoy upgrading my stuff, my question is, would upgrading to a RD such as shimano tourney and another slightly more expensive shimano cassette yield better shifting performance and durability? After adjusting my RD it shifts fairly ok, however I feel that it is very cheap and flimsy.

  • 2
    If you enjoy tinkering then buy a nicer used bike. Low end bikes are just not as serviceable.
    – paparazzo
    Oct 2, 2014 at 13:03

2 Answers 2


If its a low quality bike, you're probably best off just selling it and buying a decent bike to begin with -- there are good used road bikes for reasonably low prices.

The first problem is that cheap road bikes likely don't even have cassette+freehub systems -- they have freewheels. High quality freewheels aren't cheap, and you do need a freewheel remover of the appropriate type. It also won't really affect the shifting performance unless your rear cogs are not actually ramped for shifting.

The rear derailleur upgrade may make it stay in adjustment better, but the rear derailleur is really a "yes man" to the shifters - the shifters tell how much cable to pull and the derailleur does that subject to the limit screws not letting you shift into the spokes or out of the rear cluster,the B screw's body angle and the cable tension being good. To get good performance out of this, you'd need good shifters and a good derailleur.

Unfortunately, shifters are not cheap and have to be matched to the number of speeds in the back (unless you run friction shifters where the shifting is a continuous motion which you trim), and will likely cost more than the bike itself.

Your best option in terms of performance is to just adjust everything as well as you can and run the bike as is. When things start failing, get a new bike. If the things are so low quality that Tourney is an upgrade, pretty much anything you do will be an improvement in performance and durability but it will also cost more than the bike is worth (and you will likely to be able to buy a used bike with better quality components once you take into account the component costs (possibly even excluding tools+labor costs)).

  • 1
    Thanks for the lengthy response, I'm completely fine on spending more on components than the bike is worth, I'd even spend 3 times as much, I just enjoy tinkering. Like you stated, to upgrade the cassette I would need a special cassette removal tool? Would upgrading the RD be as simple as unscrewing it and screwing a new one in?
    – Scholar
    Oct 1, 2014 at 21:03
  • If its a freewheel (more likely on a cheap bike), you need to get the right freewheel remover (assuming its even removable - cheap freewheels often aren't and need to be destroyed in order to remove them), and then you can screw a new one on by hand. If its a cassette, you need the right remover to remove and install a new cassette. Plugging in a new rear derailleur means you need to unbolt the old one and bolt on a new one which is designed for the same cable pull as the shifters (which should be any low end Shimano), and adjust it.
    – Batman
    Oct 1, 2014 at 21:10
  • @Revoo Sheldon Brown has a good explanation of the difference between a freewheel and a cassette. sheldonbrown.com/free-k7.html
    – jimchristie
    Oct 2, 2014 at 13:10

Last year I found my girlfriend an older Takara (classic steel frame) with shimano SIS components, and it worked fine. Yes, the components were flimsy, junky, and jumped on certain gears, but it got the job done until we could upgrade it.

The next year we purchased a Trek 600 (aluminum frame) with all shimano 600 components and stripped it. We then replaced the Takara Sis components with ultergra and it is now like a brand new bike. It works better than ever. Shits like a dream, and very solid. Plus, if we ever happen to get a new frame, we have the components and the know how of installation.

Shimano is usually universal, so upgrading parts is easy. Cost of tools was about 75 dollars. But who doesn't want an excuse to buy more tools?

With bikes I have found than components make all the difference, they are truly the soul of a bike, and you will always be happier with more solid hardware.

  • There is a difference between upgrading a BSO and an old/desirable frame though.
    – Batman
    Oct 4, 2014 at 18:51

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